Serendipitous
by Mortal Anonymous
Summary: Stick with us, cuz Phineas and Ferb are gonna do it. PHINEAS/FERB LEMON WARNING!


**A/N:**** I hang the Shame Curtains for writing this story. But please, enjoy.**

The haunted house. The cuteness meter. The meteor dance. The _'romantic' cruise.._!

Isabella flipped through her past failures at attempting to woo Phineas, arranged and documented in convenient scrap book format, while curled up in her room and growing increasingly enraged. She seethed as she sourly flipped through page after page of photos depicting Phineas completely ignoring her advances.

Suddenly she slammed the book shut.

"That's it!" she defiantly declared, "I can't take this any longer! I've gotta say something! I've gotta be heard! In short: I know what I'm gonna do today!" and she stormed out of her room, making a beeline for the Flynn-Fletcher household.

…

"Phineaaaaas!"

Hearing the call, Phineas turned his head toward the sound.

"Hmm, maybe we'd better go see what that's about," he said to Ferb, "Whoever it is sounds mad…" Ferb nodded, and the two set down the heavy work table they'd been moving out to the backyard.

Walking through the gate to the front yard, Phineas brightened upon seeing who it was yelling. "Oh, hey Isabella." He greeted, not seeming to notice the angry scowl she wore.

"Don't you 'hey Isabella' me," she returned, "I have something to say to you. No more beating around the bush! Why can't you see that the love of your life is standing right in front of you, ready, devoted, waiting and willing? Why can't you see that your relationship is ready for the next level? I'm going to come right out and say this. I am going to make it perfectly clear: I want sex!" she finished loudly.

Phineas was silent a moment, before asking simply, "You think we should have sex?"

"YES!" Isabella shrieked, flying off the ground. Upon landing, she hunched over, heaving like a rabid wolf.

"O…k…" Phineas said. The screen panned slightly as he looked to the right.

"Come on then, Ferb. Let's go have 'sex'. Of course you'll have to walk me through it." Ferb gave an agreeable nod as he and Phineas walked to the backyard.

Isabella twitched.

"..Why does he always think I'm talking about the both of THEM?" she demanded disbelievingly of the air before stomping off, screaming with frustration, "I give up!"

...

Ferb strode over to the work table in the middle of the yard, where he and Phineas had left it before Isabella's interruption. Swiftly, Ferb hopped up and seated himself on the table, facing his still-standing brother.

Ferb's eyes, half-lidded, now bore into Phineas'. The mood-changing effect this had was astounding. Everything suddenly became so…stifling to Phineas.

Ferb then reached downwards, and ripped his pants and underwear off in a single motion. These he tossed aside casually.

Phineas blinked, a small blush working onto his face.

"So, I uh, guess you take your pants off for this, huh?" he asked, his mouth suddenly dry. The upturn of Ferb's lips told Phineas a big 'yes'.

As he removed his own lower garments, one at a time and more slowly than Ferb had, Phineas questioned shyly, "So, uh, then what?"

When Phineas had discarded his clothing onto the ground, Ferb, still looking directly at his brother, raised his right hand up pointedly, showing Phineas the cupped hand, before bringing it back down to begin stroking himself. His eyes closed and he leaned back momentarily at the contact, but he quickly resumed his eye contact with Phineas.

Phineas raised his own hand, looking at it curiously, but after a quick confirming glance at Ferb, mimicked the demonstrated hand position, and brought the hand downward.

Phineas gasped and his eyes bulged. "Ah! Oh, wow, that feels _good_..!"

As his hand moved, Phineas felt his eyes slide shut, and his head leaned backward. A strange fire was blooming in his gut. He made small moans of pleasure that sounded strained, as if they'd failed to be held back. His arm moved faster. He stroked, and stroked, and stroked-

Ferb snapped his fingers, breaking Phineas' trace with a 'huh?'

Ferb gave a semi-glare.

"Oh, right. Uh, am I supposed to do something else?" Nod from Ferb.

"Really?" Phineas questioned, sounding as if he doubted there was anything more gratifying than what they were doing now.

Nod.

"What?"

Ferb pointed at Phineas, and then spread his legs to point between them. Phineas stared, mouth open and drying. He coughed.

"Will I…fit in there?" he asked finally, blushing.

Ferb nodded, lying back on his elbows invitingly.

Gulping, Phineas walked forward and pulled his way up onto the work table, Ferb laying all the way back as he did, so that he was kneeling over Ferb on all fours. Heat rushed all over his body as he looked into Ferb's magnetic, sultry eyes from such a close proximity.

"So, do I just…go in all at once then, or..?" Phineas asked. Ferb shook his head and made big 'no' gestures with his hands. He then made pushing motions to signify 'sloooow'.

"O-oh, right. Gotchya." Phineas nodded, sweating nervousness. He didn't know why, but this felt like such a huge thing to be doing. He also didn't know why, but that excited him.

Ferb relaxed and closed his eyes in preparation. There was a pause.

"...Now?" asked Phineas. Ferb opened his eyes half-way again, but this time to deliver a flat look. Phineas grinned and gave a sheepish, apologetic chuckle, and Ferb resumed his previous position.

Recognizing the cue this time, Phineas carefully used his hand to aim himself before pushing himself forward with a strained grunt at the resistance. It was more difficult than expected, but it stoked his gut fire something amazing.

A sharp intake of breath from Ferb, and a slight wriggling as, inch by inch, Phineas worked his way into him.

As he was enveloped fully, the fire in Phineas spilled over and ran wild throughout his body. He let out a wavering cross between a whimper and a moan.

"Uhh!" he exclaimed, "I-it's so…warm, a-and _tight_! Oh, Ferb!" He panted heavily. Ferb lay there, adjusting, a sweat on his brow forming from his brother's hot words. He constricted and expanded alternately around Phineas, the expression on his face slowly losing all traces of pain.

When he felt loose enough, the hand he had around himself increased its pace, and he began to rock himself so that he slid up and down slightly on the table, creating friction.

Phineas' eyes became wide again as a trembling 'Ahh!' escaped him. On instinct he began to move with Ferb, hunching and moaning more as the friction increased to the point where he was starting to actually slide in and out of Ferb.

As Ferb became accustomed to the motion, the sliding became easier and more fluid. Phineas' thrusts became harder, and the pleasure for both of them mounted intensely. Ferb melted, no longer needing to rock himself to guide Phineas. He lay back, eyes closed, taking each thrust and letting the pleasure waves roll over him in droves as he stroked himself.

This went on for a while; Phineas thrusting inward, ever-enflamed by his brother's quiet gasps, the usual stoic face screwed up ever-so-slightly in ecstasy.

Eventually, however, it seemed that Ferb decided that it was Phineas' turn to lay back and enjoy. Opening his eyes, he took hold of Phineas' neck with one hand, and side with the other. Phineas barely had time to wonder what was happening before he found himself suddenly rolled over, the connection unbroken.

Now under Ferb, Phineas gawked as Ferb leaned his head back and started to rock and stroke himself again.

Going limp, Phineas let out a huge groan as his head fell back onto the table. Continuing to let out various low-pitched moans, Phineas craned his neck backwards as he felt Ferb ride him. It just felt so amazing, he couldn't hold it in. That gut fire was growing and growing..!

Phineas' moaning got louder and more urgent. He started wriggling and shaking his head back and forth.

Ferb seemed to know what this meant, because upon glancing at this change, he sped up immediately. He thrust Phineas into him at a maddening pace, pumping his arm to match it. The intensity was mounting, mounting-!

"Aaahh!" cried Phineas.

"Uuhh..!" Ferb exclaimed more quietly, rolling off of Phineas so as not to get him messed.

The two lay there, panting, side by side, letting all that had happened sink in.

At last Phineas spoke up, "That…that was…" But he was lost for words.

"'Serendipitous' is something I believe you might say." Ferb offered helpfully.

Phineas sat up and smiled warmly at Ferb. "Yeah. Yeah, serendipitous." he agreed.

Ferb sat up next to him, also smiling. Then he took the back of Phineas' head in hand and pulled the two of them together in a silent, deep and meaningful kiss before smoothly turning away and hopping off the table, retrieving his pants, draping them over his arm and making his way to the house to clean up.

Phineas stared blankly for a few seconds, but then a smile found him, and he too hopped off the table to put his pants on.

As he finished doing them up, Mom came in through the backyard gate, home from shopping, as evident by the grocery bags she carried.

"Oh. Hi, Phineas. Whatchya doin'?" Mom asked pleasantly as she spied her son.

"Ferb, apparently." Phineas beamed in reply, glancing fondly to where Ferb had disappeared.

Mom dropped her groceries.

"...WHAT?"


End file.
